Author + information
- Received June 15, 2012
- Revision received October 19, 2012
- Accepted November 20, 2012
- Published online June 4, 2013.
- *HeartFlow, Inc., Redwood City, California
- †Department of Bioengineering, Stanford University, Stanford, California
- ‡Cedars-Sinai Heart Institute, Los Angeles, California
- ↵*Reprint requests and correspondence:
Dr. James K. Min, Cedars-Sinai Medical Center, Cardiology, The Heart Institute, 8700 Beverly Boulevard, Taper Building, Room 1253, Los Angeles, California 90048.
Coronary computed tomography angiography (CTA) has emerged as a noninvasive method for direct visualization of coronary artery disease, with previous studies demonstrating high diagnostic performance of CTA compared with invasive coronary angiography. However, CTA assessment of coronary stenoses tends toward overestimation, and even among CTA-identified severe stenosis confirmed at the time of invasive coronary angiography, only a minority are found to be ischemia causing. Recent advances in computational fluid dynamics and image-based modeling now permit determination of rest and hyperemic coronary flow and pressure from CTA scans, without the need for additional imaging, modification of acquisition protocols, or administration of medications. These techniques have been used to noninvasively compute fractional flow reserve (FFR), which is the ratio of maximal coronary blood flow through a stenotic artery to the blood flow in the hypothetical case that the artery was normal, using CTA images. In the recently reported prospective multicenter DISCOVER-FLOW (Diagnosis of Ischemia-Causing Stenoses Obtained Via Noninvasive Fractional Flow Reserve) study and the DeFACTO (Determination of Fractional Flow Reserve by Anatomic Computed Tomographic Angiography) trial, FFR derived from CTA was demonstrated as superior to measures of CTA stenosis severity for determination of lesion-specific ischemia. Given the significant interest in this novel method for determining the physiological significance of coronary artery disease, we herein present a review on the scientific principles that underlie this technology.
Dr. Taylor and Mr. Fonte are employees and shareholders of HeartFlow, Inc., which provides the FFRCTA service. Dr. Min is a member of the Speaker's Bureau and medical advisory board of General Electric; and has an equity interest in TC3.
- Received June 15, 2012.
- Revision received October 19, 2012.
- Accepted November 20, 2012.
- American College of Cardiology Foundation